Dharwan 45 were subsequently attacked and 15 died; while among 3387 persons in whom a second. inoculation was made, only 2 were attacked. Haffkine uses in his inoculations a sterilised culture of the plague-bacillus. The inoculation is followed by slight fever and enlargement of the nearest lymphatic glands. All symptoms disappear at the end of two or three days. The plague-bacillus is very easily destroyed by disinfectants. Dr. Lowson reports that a 1 % solution of carbolic acid kills the bacilli within an hour, a 2% solution almost immediately. Quicklime was almost as prompt in its action. Exposure to fresh air for three or four days usually destroys the vitality of the bacillus, and exposure to direct sunlight destroys it in three or four hours. Kitasato and Yersin both arrived at the conclusion that the disease may be contracted by inoculation, through a wound or abrasion; by way of the respiratory tract when the bacillus is present in dust carried by the inspired air; or by way of the stomach when food or drink taken contains the bacillus. What has been said indicates very clearly the proper preventive measures, and when these are enforced with energy and intelligence there need be little fear of the epidemic extension of the disease. For the prevention of this and other filth diseases, our main reliance must rest upon isolation of the sick, disinfection of all infectious material, and general sanitary police of infected localities. The destruction of rats in localities infected, or likely to become so, is also a measure of prime importance. Protective inoculations will hardly be necessary if the measures above referred to are vigorously enforced, and in the opinion of the writer it is only under exceptional circumstances that such inoculations need be practised on a large scale. Those whose duties require them to care for the sick or visit infected localities may be given such protection as is afforded by Haffkine's inoculations. But the im munisation of entire communities by inoculation in anticipation of a possible plague epidemic hardly seems necessary in the present state of sanitary knowledge. CHAPTER II ASIATIC CHOLERA ASIATIC cholera has its permanent home in In dia, and especially in the thickly populated region occupied by the delta of the Ganges, the principal city of which is Calcutta. Here it prevails throughout the year, with a period of maximum intensity in the hot and comparatively dry month of April. Heavy rains have a salutary sanitary influence in this and other regions where the disease is prevalent. From the infected area referred to, the disease spreads almost annually to other parts of India and neighbouring Asiatic countries, and at intervals has extended its ravages to Africa, Europe, and America. These widespread epidemics are, however, of comparatively recent origin. After a devastating epidemic in India during the years 1816 to 1819 the disease extended to Mauritius and the east coast of Africa, to Farther India and the islands of Sumatra, Java, and Borneo, and to China. ΠΟ Two or three years later the disease prevailed in Syria and Palestine, and for the first time, so far as is known, appeared in a European country, in Astrakan. A second great epidemic, beginning in India in 1826, reached Astrakan in 1830. Thence it extended as far north as St. Petersburg. The following spring it invaded Poland and extended from Austria into Germany. At the same time it had been carried by way of Persia, Mesopotamia, Arabia, and Palestine into Egypt. Hungary, Austria, and Turkey were invaded during the same year (1831), and it finally reached Great Britain, where in 1832 it obtained wide prevalence. In this year also France, Belgium, and Holland were invaded. In 1832 it reached the United States by way of Canada, where it was carried by Irish immigrants. It spread rapidly along the St. Lawrence and the shores of Lake Ontario. By an independent importation it was brought in the same year to New York and spread thence southward and westward, invading the States of Pennsylvania, Virginia, Maryland, Kentucky, Ohio, Indiana, and Illinois, and in October first appeared in the city of New Orleans. The following summer it broke out afresh in this city and rapidly spread through the southern, central, and western States. It also invaded the Indian Territory and California. In 1834 it reappeared in the eastern States, and in 1835 was reintroduced from Cuba to the city of New Orleans. In the meantime Mexico had been invaded, and subsequently the disease obtained a limited prevalence in Central America and the Gulf coast of South America. Simultaneously with this widespread epidemic in America the disease spread in Europe to Sweden and Norway in the north and to Italy, Spain, and Portugal in the south. The disease died out during the winter of 1837-38, and for the ten following years Europe, Africa, and America remained free from this scourge of the human race. In 1846 the disease, which had previously shown increased epidemic extension in India, obtained wide prevalence in Persia, thence it extended to Arabia, and the following year reached Constantinople. In 1848 it spread through Turkey, Hungary, Asia Minor, Syria, and Egypt. In the meantime it had been introduced into Russia (in 1847), and early in the summer of 1848 reached Germany. In the autumn of this year it was introduced into England and Scotland, and the following year obtained wide prevalence in the British Isles. Holland and Belgium were invaded at the same time, and in 1849 France and Austria suffered severe epidemics. Northern Italy also suffered from the disease, which indeed prevailed in all parts of Europe, with the exception of Spain and Portugal, which countries |